Patterns and predictors of normal cognitive aging : Mentored Research Scientist Development Award (K01) in Aging. The candidate, Hiroko H. Dodge, PhD., has a strong background in demography and statistics, and substantial work experience in the epidemiology of dementia. She now proposes to move towards an independent research career in the study of healthy cognitive aging. Broadly, the K01 research goal is to study cognitive functioning over time in healthy aging population samples, and to refine the methodology used in this area. The K01 learning objectives are to gain (1) conceptual knowledge in neuropsychology, neuroscience, geriatrics, gerontology, and epidemiology, (2) practical learning in these areas through research experience;and (3) further expertise in specific statistical areas, especially in the handling of missing data bias. To refine clinical care and public health planning, it is critical to distinguish between normal and pathological cognitive aging, and to identify the patterns and predictors of normal aging. Many longitudinal studies have been conducted in non-representative clinical or volunteer populations. Other studies have suffered "missing data bias" due to the inevitable loss of data during follow up studies. There is a relative lack of data on normative age-associated cognitive trajectories, including "population norms" (ranges, averages, and percentiles in the community at large), and "healthy norms" (distribution of cognitive ability in diseasefree and disability-free individuals.) The Research Plan includes analyses of two existing longitudinal datasets, the MOVIES project (a 15- year epidemiological study in a Pennsylvanian community), the AHEAD/HRS study (an ongoing longitudinal study of a nationally representative U.S. sample), and a new pilot project within an ongoing cohort study in Shiga, Japan. The candidate will first describe longitudinal age-associated normative cognitive trajectories, applying recently developed methods in handling missing data bias. Next, she will examine the association between these norms and preserved ability to perform Instrumental Activities of Daily Living. These two approaches will allow a threshold to be defined for "healthy cognitive aging". Finally, using the above knowledge and data, she will develop a new collaborative R01 application to conduct a Japan-US cross national study of healthy cognitive aging.